HYDROLOGY AND HYDROLOGICAL CYCLE
- It is a science which concerns with the occurrence, distribution and movement of water.
- It may also be define the science that deals with the depletion and replenishment of water sources.
- When we say movement of water, it includes movement of water in atmosphere, on the surface of the earth, and below the surface of the earth.
- In atmosphere, water is present in form of vapours. On surface of earth it is in form of rivers, lakes, ponds and snow etc.
- Below the earth surface it is present in form of moist soils.
- The water occurring below the surface of the earth is known as ground water.
- Ground water occupies the voids of the soil.
- Except for the deep ground water, the total water supply of the earth remains in constant circulation between earth and atmosphere.
- This water again falls over the earth in form of precipitation.
- The part of precipitation again evaporates back to atmosphere, part is soake by the ground.
- Rivers again join the oceans and evaporation of water again occurs from them.
- The water that has percolated in to the ground either joins oceans or is brought to the surface by means of wells, infiltration gallerries etc.
- So circulation of water from earth to atmosphere and back to earth is a continuous process.
- It is this circulation of water or hydrological cycle, which keeps on using and then replenishing water.
- By measuring the elements of